Antwort: Re: explain plan and the real execution plan
- From: "Martin Klier" <Martin.Klier@xxxxxxxxxx>
- To: yong321@xxxxxxxxx
- Date: Fri, 20 Nov 2009 17:39:03 +0100
Maybe you want to have a look at this article for EXPLAIN PLANS and
EXECUTION PLANS.
Keep in mind, that things like bind peeking won't happen if you generate an
EXPLAIN_PLAN!
http://www.usn-it.de/index.php/2009/02/26/oracle-explain-or-execution-plans-guess-or-reality/
Best regards
--
Mit freundlichem Gruß
Martin Klier
Senior Oracle Database Administrator
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oracle-l-bounce@xxxxxxxxxxxxx schrieb am 20.11.2009 17:13:59:
> Von:
>
> Yong Huang <yong321@xxxxxxxxx>
>
> An:
>
> oracle-l@xxxxxxxxxxxxx
>
> Datum:
>
> 20.11.2009 17:16
>
> Betreff:
>
> Re: explain plan and the real execution plan
>
> Gesendet von:
>
> oracle-l-bounce@xxxxxxxxxxxxx
>
> In addition, if the queries against this table recently started to
> use columns not used before, the content of col_usage$ will change
> thus affecting the stats related to auto generated historgram.
>
> Yong Huang
>
> Tanel Poder wrote:
>
> > 1) The optimizer statistics
> >
> > I assume this database has no change – no ddl and dml. Under this
> > situation, I would say the optimizer statistics would remain the same,
> > correct?
>
> Even if you have no DDL and no DML happening, someone may still have
> gathered optimizer statistics on the tables and changed them. Maybe the
last
>
>
>
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
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